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Test Code Leuk Cyst Cystine, WBC

Important Note

Time sensitive draw. Samples also must be collected M - Th 0900 AM to 1400 PM in order to ship same day, and specimens should be immediately placed on ice or cold pack.

Clinical System Name

Cystine, WBC


WBC Intracellular Cystine Assay


WBC Cystine is used for initial diagnosis of Cystinosis, as well as for monitoring patients on drug therapy for Cystinosis.


Sample Requirements

Specimen: Whole Blood

Container(s): Yellow Top/ACD-Solution A

Preferred Vol: 5-10 mL

Minimum Vol: 2 mL


Notes:  Test is used for initial diagnosis and for monitoring. This is a time sensitive draw for monitoring: Patients on Cystagon are collected 5-6 hrs after their last dose. Patients on Procysbi should have sample collected right before their dose. Note drug, time of last dose on requisition, place whole blood in cold pack and transport to CPA.


Samples collected for initial diagnosis can be drawn M-TH 9 am to 2 pm; no drug information requested.



Processing Instructions

Reject due to:

Spin: N

Aliquot: N

Temp: 2-8 C

Storage location: Place whole blood on cold pack or on ice immediately and transport to CPA. Refrigerate within 1 hr. Note drug (Cystagon or Procysbi) and time of last dose on requisition.


Off-site collection: No off-site collection.


Specimen Type Temperature Time
Whole blood Refrigerated 24 hr



STAT Available TAT
N Collection M-TH dayshift only before 14:00. 21 d



Performing Laboratory

UCSD Biochemical Genetics/Cystine Lab


Department:  UCSD Biochemical Genetics/Cystine Lab, 212 Dickinson St, San Diego, CA 92103

Phone Number: (619) 543-5260


Reference Range

Interpretive report is provided.



Analytical Volume:


Clinical Utility

GeneReviews: Cystinosis


Nephropathic cystinosis in untreated children is characterized by renal tubular Fanconi syndrome, poor growth, hypophosphatemic rickets, impaired glomerular function resulting in complete glomerular failure, and accumulation of cystine crystals in almost all cells, leading to cellular destruction and tissue dysfunction.  Cystinosis is inherited in an autosomal recessive manner.

Send Out Instructions

Reference Test Name: WBC Intracellular Cystine Assay
Reference Test Number: None specified
Instructions: Ship whole blood Monday - Thursday at refrigerated temperature by FedEx. No Sat Delivery.